1. Field of the Invention
The present invention relates to an optical disk recording and reproduction method and apparatus by which defect processing is performed and a medium on which an optical disk recording and reproduction program is recorded.
2. Description of the Related Art
Optical disk recording and reproduction apparatus which have a defect function upon data writing are conventionally available.
An optical disk recording and reproduction apparatus of the type mentioned secures, if a write error of data occurs when an address X of an optical disk is accessed to write data, an alternative address Y in place of the address X and records data, which are to be recorded to the address X, to the address Y.
When the address X is to be accessed upon reading, the address Y is accessed in place of the address X to read out necessary data.
Consequently, use of a bad spot of the optical disk is eliminated thereby to raise the reliability of the optical disk.
An optical disk has a recording area which includes a user area used for recording and reproduction of normal data, a spare area secured for defect processing, and a DMA (Defect Management Area) into which correspondence between addresses of the user area and addresses of the spare area is recorded.
In the defect processing mentioned above, an address Y of the spare area is secured for the address X of the user area, and the information that the address X has been replaced by the address Y is recorded into the DMA.
However, even such data that is successfully written upon data writing sometimes becomes an error when it is read out.
In this instance, the optical disk recording and reproduction apparatus performs retrying of reading out of data so that necessary data can be read out thereby to secure the reliability upon data reading.
In particular, if a read error occurs upon data reading from an address X of an optical disk by an optical head section of an optical disk recording and reproduction apparatus, then the optical disk recording and reproduction apparatus takes the following method. In particular, the optical head section performs retrying of reading out from the address X, and the number of times of retrying is recorded into a memory each time such retrying is performed. Then, if reading out from the address X is performed successfully, then the number of times of retrying recorded in the memory is read out and compared with a prescribed number of times. If the number of times of retrying exceeds the prescribed number of times, then an alternative address Y for the address X is secured on the optical disk, and the data read out from the address X is copied to the address Y. Then, the DMA of the optical disk is rewritten so that, when a reading command for the address X is received from a host apparatus after then, data is read out from the address Y.
However, the processing of securing the alternative address Y in place of the address X on an optical disk, copying data read out from the address X to the address Y and rewriting the DMA of the optical disk so that, when a reading command for the address X is received from a host apparatus after then, data may be read out from the address Y provides a disadvantage that no sufficient time may possibly be secured to read data into the optical disk recording and reproduction apparatus and temporal specifications of an I/F (interface) may not be satisfied.
Meanwhile, as a prior art apparatus, an apparatus is disclosed in Japanese Patent Laid-Open No. 195877/1988 wherein data recorded on a recording medium is read out and, when an error of the data is higher than a predetermined reference value, the data is stored into a different memory and then next data is successively recorded onto the recording medium, and then, after the recording of a string of data onto the recording medium comes to an end, the data stored in the different memory is re-recorded onto the recording medium.
Another apparatus is disclosed in Japanese Patent Laid-Open No. 139718/1994 wherein, when an unrecoverable error occurs upon reading of a particular sector of a recording medium and a number of retrying reading operations smaller than a number of times set in advance are performed, the number of data errors upon each of the first reading operation and retrying reading operations following the first reading operation is counted and stored into a data error number storage memory.
A further apparatus is disclosed in Japanese Patent Laid-Open No. 50005/1998 wherein, when reading retrying is performed successfully with such an after-defect that requires retrying operations upon reading of a rewritable optical disk, the read data is used to perform replacement processing within the sequence to perform data compensation.
The apparatus disclosed in the documents mentioned above cannot successfully solve such a subject that no sufficient time may possibly be secured to read data into the optical disk recording and reproduction apparatus and temporal specifications of an I/F may not be satisfied as described above.
It is an object of the present invention to provide an optical disk recording and reproduction method and apparatus which suppresses a drop of the throughput of an optical disk apparatus by retrying caused by a read error and can satisfy temporal specifications of an interface.
In order to attain the object described above, according to an aspect of the present invention, there is provided an optical disk recording and reproduction method for an optical disk recording and reproduction apparatus which includes an optical head section for recording and reading out data onto and from an optical disk, a tracking section for positioning the optical head section on a track of the optical disk, a control section for controlling operation of the optical head section and the tracking section in response to a command from a host apparatus, and a memory for temporarily recording data necessary for the control by the control section, comprising the steps of causing, if a read error occurs upon reading out of data from a first address of the optical disk by the optical head section, the optical head section to perform retrying of the reading out of the first address of the optical disk and recording a number of times of retrying into the memory each time such retrying is performed, reading out, if the reading out from the first address is performed successfully, the number of times of retrying recorded in the memory, comparing the read out number of times of retrying with a prescribed number of times and, if the number of times of retrying exceeds the prescribed number of times, securing an alternate second address in place of the first address on the optical disk, and copying, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the data read out from the first address to the second address and rewriting a defect management area of the optical disk so that, when a read command for the first address is received from the host apparatus thereafter, the data may be read out from the second address.
In the optical disk recording and reproduction method, if a read error occurs upon reading out of data from a first address of the optical disk by the optical head section, then the control section controls the optical head section to perform retrying of the reading out of the first address of the optical disk and records a number of times of retrying into the memory each time such retrying is performed. Then, if the reading out from the first address is performed successfully, then the control section reads out the number of times of retrying recorded in the memory and compares the read out number of times of retrying with the prescribed number of times. If the number of times of retrying exceeds the prescribed number of times, then the control section secures an alternate second address in place of the first address on the optical disk, and performs, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the processing of copying of the data read out from the first address, to the second address and rewriting of the defect management area of the optical disk so that, when a read command for the first address is received from the host apparatus thereafter, the data may be read out from the second address. Consequently, a drop of the throughput of an optical disk apparatus by retrying caused by a read error can be suppressed and temporal specifications of an interface can be satisfied.
Thus, with the optical disk recording and reproduction method, within a free time within which none of reading processing and writing processing is being performed by the optical disk recording and reproduction apparatus, the series of processing of securing an alternate second address for a first address on an optical disk, copying data read out from the first address to the second address and rewriting the defect management area of the optical disk so that, when a read command for the first address is received, data may be read out from the second address is performed. Further, defect processing is not performed upon writing of data but performed for data which is successfully readout from the optical disk by retrying upon reading out from the optical disk. Consequently, repetition of retrying of reading out when the same address is accessed frequently can be suppressed, and as a result, the optical disk recording and reproduction method can be carried out while temporal specifications of an interface are satisfied.
According to another aspect of the present invention, there is provided an optical disk recording and reproduction apparatus, comprising an optical head section for recording and reading out data onto and from an optical disk, a tracking section for positioning the optical head section on a track of the optical disk, a control section for controlling operation of the optical head section and the tracking section in response to a command from a host apparatus, and a memory for temporarily recording data necessary for the control by the control section, the control section controlling the optical head section, the optical head section and the memory such that, if a read error occurs upon reading out of data from a first address of the optical disk by the optical head section, the optical head section performs retrying of the reading out of the first address of the optical disk and a number of times of retrying is recorded into the memory each time such retrying is performed, and if the reading out from the first address is performed successfully, then the number of times of retrying recorded in the memory is read out and compared with a prescribed number of times, and then, if the number of times of retrying exceeds the prescribed number of times, then an alternate second address in place of the first address is secured on the optical disk, whereafter, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the data read out from the first address is copied to the second address and a defect management area of the optical disk is rewritten so that, when a read command for the first address is received from the host apparatus thereafter, the data may be read out from the second address.
In the optical disk recording and reproduction apparatus, if a read error occurs upon reading out of data from a first address of the optical disk by the optical head section, then the control section controls the optical head section to perform retrying of the reading out of the first address of the optical disk and records a number of times of retrying into the memory each time such retrying is performed. Then, if the reading out from the first address is performed successfully, then the control section reads out the number of times of retrying recorded in the memory and compares the read out number of times of retrying with the prescribed number of times. If the number of times of retrying exceeds the prescribed number of times, then the control section secures an alternate second address in place of the first address on the optical disk, and performs, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the processing of copying of the data read out from the first address to the second address and rewriting of the defect management area of the optical disk so that, when a read command for the first address is received from the host apparatus thereafter, the data may be read out from the second address. Consequently, a drop of the throughput of an optical disk apparatus by retrying caused by a read error can be suppressed and temporal specifications of an interface can be satisfied.
Thus, with the optical disk recording and reproduction apparatus, within a free time within which none of reading processing and writing processing is being performed by the optical disk recording and reproduction apparatus, the series of processing of securing an alternate second address for a first address on an optical disk, copying data read out from the first address to the second address and rewriting the defect management area of the optical disk so that, when a read command for the first address is received, data may be read out from the second address is performed. Further, defect processing is not performed upon writing of data but performed for data which is successfully read out from the optical disk by retrying upon reading out from the optical disk. Consequently, repetition of retrying of reading out when the same address is accessed frequently can be suppressed, and as a result, the optical disk recording and reproduction method can be carried out while temporal specifications of an interface are satisfied.
According to a further aspect of the present invention, there is provided a medium on which an optical disk recording and reproduction program is recorded, the optical disk recording and reproduction program causing an optical disk recording and reproduction apparatus to execute the steps of causing, if a read error occurs upon reading out of data from a first address of an optical disk by an optical head section of the optical disk recording and reproduction apparatus, the optical head section to perform retrying of the reading out of the first address of the optical disk and recording a number of times of retrying each time such retrying is performed, reading out, if the reading out from the first address is performed successfully, the recorded number of times of retrying, comparing the read out number of times of retrying with a prescribed number of times and, if the number of times of retrying exceeds the prescribed number of times, securing an alternate second address in place of the first address on the optical disk, and copying, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the data read out from the first address to the second address and rewriting a defect management area of the optical disk so that, when a read command for the first address is received from a host apparatus thereafter, the data may be read out from the second address.
On the medium, the optical disk recording and reproduction program is recorded which causes an optical disk recording and reproduction apparatus to execute the steps of causing, if a read error occurs upon reading out of data from a first address of an optical disk by an optical head section of the optical disk recording and reproduction apparatus, the optical head section to perform retrying of the reading out of the first address of the optical disk and recording a number of times of retrying each time such retrying is performed, reading out, if the reading out from the first address is performed successfully, the recorded number of times of retrying, comparing the read out number of times of retrying with a prescribed number of times and, if the number of times of retrying exceeds the prescribed number of times, securing an alternate second address in place of the first address on the optical disk, and copying, when the optical disk recording and reproduction apparatus is performing none of reading processing and writing processing for the optical disk, the data read out from the first address to the second address and rewriting a defect management area of the optical disk so that, when a read command for the first address is received from a host apparatus thereafter, the data may be read out from the second address. Therefore, if the medium is applied to an optical disk recording and reproduction apparatus, then the optical disk recording and reproduction apparatus operates in accordance with the optical disk recording and reproduction program. Consequently, a drop of the throughput of the optical disk recording and reproduction apparatus by retrying caused by a read error can be suppressed and temporal specifications of an interface can be satisfied.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference symbols.